This invention relates to a card connector for use with various kinds of electronic appliances such as, for example, a mobile phone or cellular telephone, a digital camera and the like.
The electronic appliances such as mobile phone and digital camera are usually constructed to enable the loading of an IC card (integrated circuit card) in which CPU or IC for memory is built, such as multimedia card®, for the purpose of extensions of various functions.
Widely used as means for detachably loading such an IC card onto the electronic appliances are card connectors in which a plurality of contact terminals 102 are provided in a connector housing 101 as shown in FIGS. 7a and 7b. These contact terminals 102 are adapted to be connected to various electric circuits (not shown) on the side of an electronic appliance. As shown in FIG. 8, when a card 103 is inserted in the card connector, contact portions 108 of the contact terminals 102 each become in electrically contact with a contact pad 106 received in each of recesses 105 formed in the front end 104 of the IC card 103, thereby electrically connecting the contact pads 106 of the IC card 103 and the contact terminals 102 of the card connector 100. The card connector 100 and the IC card 103 thus in the connected relation are connected to an electronic appliance, thereby enabling the exchange of electric signals or information between the IC card 103 and the electronic appliance.
Usually, contact terminals 102 of a card connector 100 are made of an electrically conductive material having a springiness by means of which a contact force can be obtained between the contact pads 106 of the IC card 103 and the contact terminals 102 of the card connector 100 when the IC card 103 has been normally inserted into the card connector 100.
With the contact force utilizing the springiness of the contact terminals 102, however, when numerous insertions and removals of cards into and from the card connector have been effected, the springiness of the contact terminals 102 would be deteriorated due to fatigue and the like so that sometimes no sufficient contact force therebetween would be obtained, resulting in electrically failed connection.
In addition, if an IC card 103 is wrongly inserted with its rear end 107 into the card connector 100 as shown in FIG. 9, the contact portion 108 of each of the contact terminals 102 would be urged downwardly in excess of the elastic deformation, with the result of plastic deformation of the contact terminals 102. Thereafter, even if an IC card 103 is correctly inserted into the card connector 100, it is more difficult to obtain a sufficient contact force between the contact terminals and the contact pads of the card.
Consequently, there is a need for obtaining suitable contact force between the contact pads 106 of the IC card 103 and the contact terminals 102 of the card connector 100 even after IC cards have been normally repeatedly loaded into the card connector. However, we could not find any means for achieving the suitable contact force in known literatures.